Internal-combustion engine



May 5, 1953 Filed Aug. 5, 1948 w. w. CUSHMAN INTERNAL-COMBUSTION ENGINE 2 SHEETSSHEET 1 INVENTOR.

iffy/Whey Patented May 5," 1953 *1 Claims;

sec.

The invention described herein; if, patented; may he manufactured and used by or ion the Government for: governrnen'talv purposes, without the'pavment to; me of any royalty thereon.

This invention relates to internaicombustion engines and has, for its primary object, to. in.- crease the. economyand. eificieney of an engine oftl'xis' type by so constructing the same as. to, it to operate; at a constant compression ratio at all times;

Another object of the invention resides in: constructing an internal combustion en ine which will: omeratain a manner to consume practically. am of'tfie fuel supplied to. the cylinders thereby reducing the; formation of poisonous gases such as carbon monoxide et'cx, v

A iin'thcr object of the invention, consists. in theformationof an internal combustion engine. such that the tendency to pump. oil is' entirely eliminated I finotheno'loject of the invention: resides in the provision of an internal combustion engine. in which the; specific heat of the intake mixture at? part throttle is suhstantiallvincreased, there- By providing" better internal cooling of the engineand reducing the tendency towards; detonatingthe charges in normal" running of; the

engine.

A sti-ll further object of the. invention, consists in the providing of an internal combustion en.- ginewhich is capable of generating, greater power at lowerthrottl'e settin than can be generated by conventional engines having the same mum.-

and. size of cylinders and the same,v piston stroke.

Other objects and advantagesofj' the: invention wlllibe apparent from the following: description hearted-ken irr'connecti'on with the accompanying drawin s. in Which 1 Figure 1' is' a side elevational View of a, conventional internal combustion engine having purtsbrohen away: I

Retire 2% is art enlarged sectional. detailed view at the upper end of the radiator,

Figure 3 is a sectional detailed View of the upper end: of the overflow pipe of the radiator, and,

Figure 4 is a iragmentary elevation-ah view partly broken away of a siightly modified construction In the present illustration, of the invention,

indicatedby the 'o umeralband is. provided with the; usual intake manifold 2,, exhaust manifold 3 exhaust, pipe 4 and mufiiert 5. The.- numeral 6 designates; a conventionat radiator provided with inlet-and exhaust pipes I! and 8 respectively, communicating with the cooling. systemi. at the 2 engine, the carburetor is indicated, by the; numeral 9i and the throttle valve by numeral ll. As already: mentioned, a primarv objeot of theinvention isto so modify the modern internal combustion, engine as to cause it: to operate at a constant-compression. ratio at all times and to this end provision is made for conveying a'portion, of. the exhaust gases'from the exhaust pipe or tail to the intake lineof the engine between the. carburetor and the intake manifold. In other wor ds, the exhaust, gases enter the intake line after carburetion, Moreover; the construction' is such as to vary the amount of; exhaust gases entering a, cylinder in inverse proportion to the amount of carbureted fuel and air'. The fluid line. for conveying exhaust gases from the: tail pipeof the engineincludes a pipe Ii connected to-the tail pipe. adjacent: the muiiiei:

'5 as indicated by'numeral" l2 and this pipe may include a filter [3,} which serves to eliminate foreign; matter and also toaid in cooling the exhaust gases prior to, their entrance into "the intakemanifoldz Also, the fact thatth'e pipe 8 l is: connected to theexhaust pipe at a point ad- Jacent the muiiier; provides that theexhaust gases will have lost a considerable portion of their heat before entering thepipe ii and. there will be a substantial additional drop in temperature of the exhaust gases as they are conveyed along the pipe; H to the interior of the radiator ii. The pipe H has" at. least; one portion thereof for in stancehthe ortionj. M extending to a point above the normal level of'water inthe radiator so that the water fromthe radiator will not be: permitted to discharge into the pipe H; as this pipe i-i 'ha's its forward end connected with the cooiing' s'ys-c tom of the engine: adjacent the pipe I which carries; the. heated water from the system into thelra'diator' and the exhaust gases, as indicated by thea'rrow's, allowing" gas'to bubble-up through the, water the pipe 'i-and in the upper portion of the radiator into the space at the top or the radiator: v j

From the top. of the radiator the exhaust gases are drawn through a pipel5; entering the intake line of the. engine between-- the carburetor and intakemanifol'd asindicated by the rmmerai l 6. The opposite end oithe'pipe l't-may be connected to the radiator by any preferred means, but in the present disclosure, it is connected to the ra-di'atcn ata point adjacent the radiator cap 1! as indieated by numeral ra It is thus apparent that the upper portion of' the radiator isopen to the negativepressures'oi'eated-in the intake maniifiold and, therefore, it is necessary that the radiator he completely closed to the-atmosphere eitherby so; constructing the: radiator originally qr by 01081 18 theconventionalioverflow i eg m 3 the present instance, the overflow pipe is indicated (Fig. 3) by the numeral l9 and may be closed by a screw plug 20 connected to the usual radiator cap I! by flexible connection 21 to which the plug 20 may be swivelly connected.

It will be apparent from the above description that the fluid line for conveying a portion of the exhaust gases from the exhaust line of the engine to the intake line includes the pipe I l, the pipe I of the cooling system of the engine, the upper portion of the radiator and the pipe I5 which provides communication between the radiator and the intake line of the engine. The exhaust gases which enter the intake manifold and the cylinder of the engine are cooled in the various ways indicated above and also as they enter and pass through the water in the cooling system, that is, the pipe 1 and the head of water above the exit opening of the pipe I in the radiator 6. These cooled gases enter the intake line of the engine at the point l6 and the proportion of exhaust gases to the carbureted fuel entering the intake manifold, and consequently the cylinders of the engine, is varied in accordance with the position of the throttle valve I0. When the throttle valve I is wide open, there will be no suction whatever on the pipe l5 and accordingly no exhaust gases will enter the intake line. However, as the throttle valve is moved away from its fully opened position, the degree of suction on the pipe l5 increases in the amount of exhaust gases entering the intake line and when the throttle valve I0 is completely closed a full charge of exhaust gases will enter the intake line and the cylinders, except, of course, for the small amount of live fuel which is always provided for idling of the engine. With this arrangement, therefore, it will be noted that the engine cylinders are fully charged with gases of one kind or the other throughout the operation ofthe engine, thus increasing its efiiciency of operation by providing the constant compression ratio for which the particular engine is designed. By thus fully charging the cylinders in all operations of the engine at all speeds and under any loads to which it may be subjected, many advantages flow. For instance, no carbon monoxide will be formed since the gasoline vapors will be fully consumed when the cylinders are fullycharged and the gases are ignited at the full compression for which the engine isdesigned, Also, there can be no pumping of lubricating oil past the engine pistons due to the fact that no vacuums or partial vacuums-are formed in the cylinders under this manner of operation. Moreover, the specific heat of the intake mixture, at part throttle, is substantially increased due to the picking up of moisture in passing through the water in the radiator, thereby providing better internal cooling of the engine and eliminating the possibility of detonating the charges. And again, the construction described herein is capable of generating greater power than is generated by conventional engines of the same size to the uniformly higher pressures in the cylinders at the time of ignition of the charges through the operation of the engine.

In Figure 4 is shown a construction substantially identical with that heretofore described and shown in Figures 1 to 3 inclusive, except that in this latter form of invention, the throttle valve, which is indicated by the numeral 30, is situated so as to contact the inner end of pipe IS, the latter extending to substantially the center line of the intake line as indicated by the numeral 3|. Mounted on the side of the throttle valve adjacent the end 3| of pipe I5 is a substantially cone-shaped or horn-shaped plug 32 which is located as to completely enter and close the end of end 3| of the pipe when the throttle valve itself is in fully open position as indicated in dotted lines in Figur 4. With this shape of the plug 32, it will be apparent that the pipe 3| will be opened gradually as the throttle valve 30 moves toward its closed position, and on the other hand, will be closed gradually as the throttle valve 30 is moved towards its opened position, thereby providing for a gradual increase in the flow of exhaust gases into the intake line and for a gradual shutting off of the flow as the case may be. Otherwise, the construction and operation of this form of the invention is identical with that shown in Figures 1 to 3 inclusive.

In accordance with the patent statutes, I have described the preferred forms of construction and the preferred method of operation of the present internal combustion engine, but it is obvious that the structural details as well as the steps involved in the method of charging the cylinders may be varied without departing from the spirit of the invention and it is intended that all such changes be included within the scope, of the appended claims. l 4

I claim:

1. In an otherwise conventional internal combustion engine, an exhaust line, a radiator closed to the atmosphere, a fluid line leading from the exhaust line to the radiator at a point below the normal water level, and a second fluid line leading from the radiator at a point above the water line to the intake line. 1

2. In an otherwise conventional internalcombustion engine, an exhaust line, a radiatorclosed to the atmosphere, a fluid line leading from the exhaust line at a point adjacent the niufiier to the radiator at a point below the normal water level, and a second fluid line leading frornthe radiator at a point above the .water line to the intake line at a point between the carburetor and intake manifold. I

3. In an otherwise conventional internal combustion engine, an exhaust line, a radiator, means for closing the overflow pipe of the radiator, means for conveying exhaust gases from the exhaust line to a point below the water level in the radiator, and means for conveying exhaust gases from a point above the water level in the radiator to the intake line. a

4. In an otherwise conventional internal combustion engine, an exhaust line, a radiator, means for closing the overflow pipe of the radiator, means for conveying exhaust gasesfrom the exhaust line to a point below the water level in the radiator, a filter in said exhaust conveying means, and means for conveyingexhaust gases from a point above the water level in the radiator to the intake line.

WALTON W. CUSHMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date" 911,345 Tait et al. Febf2 1909 1,440,956 Ballenger Jan. 2, 1923 7 1,453,560 Whetstine May 1,1923 1,459,794 Patty June 26 1923 2,099,802 Ewing Nov, '23 1937 2,300,774 Cartmell Nova 3: 1942 2,354,179 Blanc J'u1 '25',-'-i i4 

